The funny thing is that, not only were the Ptolemies all Macedonians (and light-haired Macedonians at that), but because they had that terrible habit of MARRYING THEIR FULL SISTERS and, in some cases, nieces or adopted daughters and having children with them, it's hard to even try to make a straw-man argument of "one of the queens could have been native Egyptian".

Even if we were to accept that, though, we know what the Egyptians looked like. Anyone doubting these need only look at the masterful portraiture of the Roman-era sarcophagi (called "Fayyum sarcophagi" because of their preponderance around Fayyum). Egyptians looked very Semitic back then.

Even if one were to reject the Fayyum sarcophagi, we have wall paintings that distinguish Egyptians from their Nubian neighbors to the south.

It's just a peculiarly American black phenomenon, and even in the American black community it's restricted to a neo-"black power" sort of movement. And it's absurd. It's also pretty much irrelevant.